The present invention relates to a disk cartridge which contains an information carrying disk such as an optical disk or a magneto-optical disk in a manner to permit its insertion and removal.
A conventional disk cartridge which is commercially available in the trade name of "electronic book" is illustrated in FIG. 34 to FIG. 38. Specifically, FIG. 34 is a plan view of an upper side of the disk cartridge (corresponding to A-side of the disk), FIG. 35 is a plan view of the upper side, illustrating the manner of opening a shutter of the disk cartridge shown in FIG. 34, and FIG. 36 is a plan view of a lower side (corresponding to B-side of the disk), illustrating the manner of opening the shutter of the disk cartridge shown in FIG. 34. Further, FIG. 37 is a cross section of the disk cartridge shown in FIG. 34 taken along the line S.sub.37 --S.sub.37 shown in FIG. 34, and FIG. 38 is a plan view illustrating a manner of removing the disk from the disk cartridge shown in FIG. 34 by opening a lid of the cartridge.
As shown in FIG. 34 to FIG. 38, a conventional disk cartridge includes a case 1 which contains a disk 5 in a rotatable manner. The case 1 includes an upper member 2 and a lower member 3 which are disposed opposite to each other with a given spacing therebetween to define a space 4 in which the disk 5 is received. The upper member 2 includes an upper planar portion 6 of the case 1, and a part of the walls 7, 8, 9 and 10 of the case 1, which substantially correspond to one-half thereof. Similarly, the lower member 3 includes a lower planar portion 11 of the case 1, and a part of the walls 7, 8, 9 and 10 of the case 1, which substantially correspond to one-half thereof.
The upper member 2 is provided with a window 2a through which information is written into or read from the A-side of the disk 5. Similarly, the lower member 3 is provided with a window 3a through which information is written into or read from the B-side of the disk 5. The case 1 is also provided with a shutter 12 which opens or closes the windows 2a and 3a.
The wall 10 of the case 1 is formed with an opening 13 which permits the disk 5 to be inserted into or removed from the case 1. The case 1 is provided with a lid 14 which opens or closes the opening 13. The lid 14 is supported by the case 1 so as to be pivotable about a pivot 15 in a plane parallel to the upper and the lower planar portions 6 and 11 of the upper and the lower members 2 and 3.
In the conventional disk cartridge as mentioned, the lid 14 is formed with an end face 14a which is located on the outside of the end faces 2b and 3b of the upper and the lower members 2 and 3 so as to cover these end faces 2b and 3b. Accordingly, when a locking mechanism for the lid 14 (not shown in FIG. 34 to FIG. 38) is unlocked to open the lid 14, there is a likelihood that undue forces may be applied to the lid 14 to cause a plastic deformation thereof, thereby degrading the accuracy of the end face 14a of the lid 14. Also, when the lid 14 is closed, if the lid 14 is locked imperfectly, the end face 14a which is urged by a hand assembly of a disk changer mechanism (not shown in FIG. 34 to FIG. 38) assumes a slant position, again degrading the accuracy. Accordingly, in either instance, when the hand assembly of the disk changer mechanism presses the end face 14a of the lid 14 to move the disk cartridge into a record/playback unit, the disk cartridge may be forcibly inserted while the disk cartridge assumes the slant position. In worst cases, the disk cartridge may be jammed within the record/playback unit to disable either insertion or removal of the disk cartridge.
In addition, there is a problem that when removing the disk 5 from the disk cartridge, the information carrying surface of the disk 5 may come into contact with the end faces 2b and 3b or the internal surfaces of the upper and the lower members 2 and 3, whereby the information carrying surface of the disk 5 may be scarred.
In addition, when inserting the disk 5 into the disk cartridge, dust which is electrostatically attracted or hand-grease may be deposited upon the information carrying surface of the disk 5, interfering with or preventing read-out of the information from the disk 5.
The absence of a mechanism which guides the disk 5 when it is to be received within the disk cartridge may cause the disk 5 to be dropped in the course of containing it into the disk cartridge, or cause the information carrying surface of the disk 5 to be brought into contact with the internal surfaces of the case 1, or cause a deposition of the hand-grease or the like upon the information carrying surface of the disk 5.
Also absent is a mechanism which detects whether the disk 5 has never been removed from the disk cartridge or whether it has been removed at least once. Accordingly, when it is desired to record information, an operation to distinguish whether or not a normal recording operation is possible or an operation to verify the format of the disk 5 must be executed before a record operation can be initiated, increasing the length of time required for the record operation.
Finally, the opening 13 of the disk cartridge is of a size which permits a plurality of varieties of disks such as MD (trade name: mini-disk) or disk used as an electronic book to be directly inserted into the disk cartridge, presenting a problem that a different type of disk other than intended may be inadvertently inserted into the disk cartridge.